This competing continuation application seeks support for a training program in Endocrine and Metabolic research at Boston University School of Medicine (BUSM). The Program is presently in its 44th year and has trained many world-renowned investigators. Its aim is to prepare qualified pre- and post-doctoral trainees for careers as independent investigators in diabetes, obesity and metabolic disorders, and selected aspects of endocrinology. Training will take place in the sections of Endocrinology, Diabetes, and Nutrition, Molecular Medicine, Geriatrics and Cardiology in the Department of Medicine, and the departments of Biochemistry and Biophysics-Physiology, the Section of Epidemiology at the Boston University School of Public Health, the BU General Clinical Research Center, the Boston Obesity and Nutrition Research Center, Diabetes and Vascular Biology units, and Muscle and Aging Research Unit. The 23 members of the program faculty are presently recipients of 72 research grants funded by the NIH or major foundations, including 56 grants in which they serve as principal investigators. Special areas of strength include diabetes and its vascular complications, obesity, insulin secretion and action, adipose tissue biology, vitamin D metabolism and actions, genetic epidemiology of metabolic disorders, and androgen biology and mechanisms of action. An Executive Committee consisting of the program director, the three co-directors and four other investigators will select pre- and post-doctoral fellows and evaluate the trainees and their mentors. An Advisory Panel (Provost Antman, and Drs. Coleman, Meenan, and Franzblau) will evaluate the performance of the program directors and the effectiveness of the program. Based on our recent experience, approximately half of our pre-doctoral trainees are expected to be M.D.-Ph.D. candidates. An intensive interdisciplinary research experience will be complemented by incorporation of required course work into each individual's training plan. As before, only M.D. fellows who choose to enter a program leading to a Ph.D., M.P.H. or another graduate degree, or who have shown evidence of commitment to an academic career will be admitted. The Program's strengths include an outstanding faculty, substantial NIH grant support, a large pool of highly qualified applicants, a vigorous infrastructure for interdisciplinary research, and high retention rates of trainees in academia. Over 90% of our pre-and post-doctoral trainees and 100% of our MD fellows who completed the program in the past five years have continued in academia. Because of the remarkable growth of diabetes, obesity, and endocrine research at BUSM, and increasing numbers of outstanding pre- and post-doctoral applicants, especially pre-doctoral M.D.-Ph.D. candidates, expansion of the program from 6 (3 pre-doctoral and 3 post-doctoral) to 7 positions (4 pre-doctoral and 3 post-doctoral) is requested.